The determination of the sedimentary facies in a subsoil is often a necessary step in determining the capacity of this subsoil to trap hydrocarbons.
A facies serves to describe a litho-stratigraphic stage, a rock or a mineral. For example, it is possible to speak of an isometric facies (minerals/rocks exhibiting substantially equal dimensions in the three directions in space such as galena or garnet), of an elongated facies (minerals/rocks exhibiting developed crystals spreading in a single direction), of a tabular facies (minerals/rocks exhibiting developed crystals spreading in two directions in space), etc.
To determine these facies, it may be useful to produce drillholes at various points of interest. Thus, it is possible on the basis of drill cores to determine the various facies vertically as a function of depth.
Nonetheless, these drillholes being necessarily pointlike, the facies outside of these drillholes remain unknown. Certain geostatistic procedures propose filling in the gap in knowledge between the drilling wells by interpolating the facies between the wells as a function of the variance and by taking into account the spatial distribution of these facies.
Such procedures are not devoid of defects.
Indeed, these procedures do not take into account the data originating from seismic sources though the latter may give useful information as regards the orientations of the former sedimentary facies in the domain studied, for example, the orientation of the former channels.
Moreover, these procedures do not take into account the information according to which certain lithographic layers of different wells are connected together.
There is thus a need to improve the existing subsoil modeling procedures so as to take certain of this information into account.
The present invention therefore improves the situation.